The present invention relates to shredding machines (“shredders”), for example those used in homes and offices for destroying sensitive or confidential materials, including paper documents, compact discs, credit cards, etc. Certain circumstances can result in a jam, wherein material being processed through the cutters of the shredder is not able to be fully processed in continuous forward operation. Some users may be aware that running the shredder back-and-forth between forward and reverse operation can potentially clear a jam, but others may not. Even if a user is compelled to run the shredder back-and-forth between forward and reverse operation, they may be uncertain as to how long to run in each direction, or when to change directions,